Control of coolant temperature in energy storage enclosure

Abstract

A method of controlling temperature of a coolant supplied to a battery pack includes detecting a request for charging the battery pack, and commanding, via the electronic controller, a rate of charge of the battery pack. The method also includes determining the dew point inside the battery pack during the charging. The method additionally includes commanding a supply of coolant to the battery pack while the battery pack is charging. The method also includes regulating a temperature of the coolant to maintain the battery pack above the determined dew point during the charging. The method may further include maximizing the rate of charge at the regulated temperature of the coolant. A battery system employing an electronic controller configured to perform such a method, and a motor vehicle using such a battery system are also within the scope of the present disclosure.

What is claimed is: 
     
         1 . A method of controlling temperature of a coolant supplied to a battery pack, the method comprising:
 detecting, via an electronic controller, a request for charging the battery pack;   commanding, via the electronic controller, a rate of charge of the battery pack;   determining, via the electronic controller, a dew point inside the battery pack during the charging;   commanding, via the electronic controller, a supply of coolant to the battery pack while the battery pack is charging; and   regulating, via the electronic controller, a temperature of the coolant to maintain the battery pack above the determined dew point during the charging.   
     
     
         2 . The method of  claim 1 , wherein determining the dew point includes:
 detecting, via a first sensor in communication with the electronic controller, a characteristic indicative of temperature inside the battery pack;   detecting, via a second sensor in communication with the electronic controller, a characteristic indicative of humidity inside the battery pack; and   using the respective characteristics detected by the first and second sensors in a look-up table to determine the dew point inside the battery pack.   
     
     
         3 . The method of  claim 2 , wherein the battery pack includes a battery pack housing, and wherein the first and second sensors are arranged inside the battery pack housing. 
     
     
         4 . The method of  claim 2 , further comprising setting, via the electronic controller, the temperature of the coolant above a first threshold temperature selected to minimize lithium plating inside the battery pack. 
     
     
         5 . The method of  claim 2 , further comprising setting, via the electronic controller, the temperature of the coolant above a second threshold temperature selected to minimize condensation inside the battery pack. 
     
     
         6 . The method of  claim 2 , wherein setting the temperature of the coolant includes heating the coolant to maintain the battery pack above the determined dew point during the charging. 
     
     
         7 . The method of  claim 2 , wherein:
 the battery pack is arranged inside a motor vehicle having a vehicle cabin;   the characteristic indicative of temperature inside the battery pack is temperature inside the vehicle cabin and the characteristic indicative of humidity inside the battery pack is humidity inside the vehicle cabin;   the first sensor is configured to detect the temperature directly inside the vehicle cabin, and the second sensor is configured to detect the humidity directly inside the vehicle cabin; and   determining the dew point includes rationalizing, via the electronic controller, the dew point inside the battery pack during the charging in response to the detected temperature inside the vehicle cabin and the detected humidity inside the vehicle cabin.   
     
     
         8 . A battery system comprising:
 a battery pack; and   an electronic controller configured to:
 detect a request for charging the battery pack; 
 command a rate of charge of the battery pack; 
 determine a dew point inside the battery pack during the charging; 
 command a supply of coolant to the battery pack while the battery pack is charging; and 
 regulate a temperature of the coolant to maintain the battery pack above the determined dew point during the charging. 
   
     
     
         9 . The system of  claim 8 , further comprising:
 a first sensor configured to detect a characteristic indicative of temperature inside the battery pack; and   a second sensor configured to detect a characteristic indicative of humidity inside the battery pack;   wherein the controller is configured to use the respective characteristics detected by the first and second sensors in a look-up table to determine the dew point inside the battery pack.   
     
     
         10 . The system of  claim 9 , wherein the battery pack includes a battery pack housing, and wherein the first and second sensors are arranged inside the battery pack housing. 
     
     
         11 . The system of  claim 9 , wherein the electronic controller is additionally configured to set the temperature of the coolant above a first threshold temperature selected to minimize lithium plating inside the battery pack. 
     
     
         12 . The system of  claim 9 , wherein the electronic controller is additionally configured to set the temperature of the coolant above a second threshold temperature selected to minimize condensation inside the battery pack. 
     
     
         13 . The system of  claim 9 , wherein the electronic controller is additionally configured to set the temperature of the coolant by commanding heating of the coolant to maintain the battery pack above the determined dew point during the charging. 
     
     
         14 . The system of  claim 9 , wherein:
 the battery pack is arranged inside a motor vehicle having a vehicle cabin;   the characteristic indicative of temperature inside the battery pack is temperature inside the vehicle cabin and the characteristic indicative of humidity inside the battery pack is humidity inside the vehicle cabin;   the first sensor is configured to detect the humidity directly inside the vehicle cabin; and   the electronic controller is additionally configured to determine the dew point by rationalizing the dew point inside the battery pack during the charging in response to the detected temperature inside the vehicle cabin and the detected humidity inside the vehicle cabin.   
     
     
         15 . A motor vehicle comprising:
 an electric motor-generator;   a battery pack configured to supply an electric current to the electric motor-generator; and   an electronic controller configured to:
 detect a request for charging the battery pack; 
 command a rate of charge of the battery pack; 
 determine a dew point inside the battery pack during the charging; 
 command a supply of coolant to the battery pack while the battery pack is charging; and 
 regulate a temperature of the coolant to maintain the battery pack above the determined dew point during the charging. 
   
     
     
         16 . The motor vehicle of  claim 15 , further comprising:
 a first sensor configured to detect a characteristic indicative of temperature inside the battery pack; and   a second sensor configured to detect a characteristic indicative of humidity inside the battery pack;   wherein the controller is configured to use the respective characteristics detected by the first and second sensors in a look-up table to determine the dew point inside the battery pack.   
     
     
         17 . The motor vehicle of  claim 16 , wherein the battery pack includes a battery pack housing, and wherein the first and second sensors are arranged inside the battery pack housing. 
     
     
         18 . The motor vehicle of  claim 16 , wherein the electronic controller is additionally configured to set the temperature of the coolant above the higher of a first threshold temperature selected to minimize lithium plating inside the battery pack and a second threshold temperature selected to minimize condensation inside the battery pack. 
     
     
         19 . The motor vehicle of  claim 16 , wherein the electronic controller is additionally configured to set the temperature of the coolant by commanding heating of the coolant to maintain the battery pack above the determined dew point during the charging. 
     
     
         20 . The motor vehicle of  claim 16 , further comprising a vehicle cabin, wherein:
 the characteristic indicative of temperature inside the battery pack is temperature inside the vehicle cabin and the characteristic indicative of humidity inside the battery pack is humidity inside the vehicle cabin;   the first sensor is configured to detect the temperature directly inside the vehicle cabin, and the second sensor is configured to detect the humidity directly inside the vehicle cabin; and   the electronic controller is additionally configured to determine the dew point by rationalizing the dew point inside the battery pack during the charging in response to the detected temperature inside the vehicle cabin and the detected humidity inside the vehicle cabin.